Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2017 Linaro Ltd.
 */
 
#include <linux/kernel.h>
#include <linux/cdev.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/of_reserved_mem.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/qcom_scm.h>
 
#define QCOM_RMTFS_MEM_DEV_MAX	(MINORMASK + 1)
 
static dev_t qcom_rmtfs_mem_major;
 
struct qcom_rmtfs_mem {
<------>struct device dev;
<------>struct cdev cdev;
 
<------>void *base;
<------>phys_addr_t addr;
<------>phys_addr_t size;
 
<------>unsigned int client_id;
 
<------>unsigned int perms;
};
 
static ssize_t qcom_rmtfs_mem_show(struct device *dev,
<------><------><------>      struct device_attribute *attr,
<------><------><------>      char *buf);
 
static DEVICE_ATTR(phys_addr, 0444, qcom_rmtfs_mem_show, NULL);
static DEVICE_ATTR(size, 0444, qcom_rmtfs_mem_show, NULL);
static DEVICE_ATTR(client_id, 0444, qcom_rmtfs_mem_show, NULL);
 
static ssize_t qcom_rmtfs_mem_show(struct device *dev,
<------><------><------>      struct device_attribute *attr,
<------><------><------>      char *buf)
{
<------>struct qcom_rmtfs_mem *rmtfs_mem = container_of(dev,
<------><------><------><------><------><------><------>struct qcom_rmtfs_mem,
<------><------><------><------><------><------><------>dev);
 
<------>if (attr == &dev_attr_phys_addr)
<------><------>return sprintf(buf, "%pa\n", &rmtfs_mem->addr);
<------>if (attr == &dev_attr_size)
<------><------>return sprintf(buf, "%pa\n", &rmtfs_mem->size);
<------>if (attr == &dev_attr_client_id)
<------><------>return sprintf(buf, "%d\n", rmtfs_mem->client_id);
 
<------>return -EINVAL;
}
 
static struct attribute *qcom_rmtfs_mem_attrs[] = {
<------>&dev_attr_phys_addr.attr,
<------>&dev_attr_size.attr,
<------>&dev_attr_client_id.attr,
<------>NULL
};
ATTRIBUTE_GROUPS(qcom_rmtfs_mem);
 
static int qcom_rmtfs_mem_open(struct inode *inode, struct file *filp)
{
<------>struct qcom_rmtfs_mem *rmtfs_mem = container_of(inode->i_cdev,
<------><------><------><------><------><------><------>struct qcom_rmtfs_mem,
<------><------><------><------><------><------><------>cdev);
 
<------>get_device(&rmtfs_mem->dev);
<------>filp->private_data = rmtfs_mem;
 
<------>return 0;
}
static ssize_t qcom_rmtfs_mem_read(struct file *filp,
<------><------><------>      char __user *buf, size_t count, loff_t *f_pos)
{
<------>struct qcom_rmtfs_mem *rmtfs_mem = filp->private_data;
 
<------>if (*f_pos >= rmtfs_mem->size)
<------><------>return 0;
 
<------>if (*f_pos + count >= rmtfs_mem->size)
<------><------>count = rmtfs_mem->size - *f_pos;
 
<------>if (copy_to_user(buf, rmtfs_mem->base + *f_pos, count))
<------><------>return -EFAULT;
 
<------>*f_pos += count;
<------>return count;
}
 
static ssize_t qcom_rmtfs_mem_write(struct file *filp,
<------><------><------>       const char __user *buf, size_t count,
<------><------><------>       loff_t *f_pos)
{
<------>struct qcom_rmtfs_mem *rmtfs_mem = filp->private_data;
 
<------>if (*f_pos >= rmtfs_mem->size)
<------><------>return 0;
 
<------>if (*f_pos + count >= rmtfs_mem->size)
<------><------>count = rmtfs_mem->size - *f_pos;
 
<------>if (copy_from_user(rmtfs_mem->base + *f_pos, buf, count))
<------><------>return -EFAULT;
 
<------>*f_pos += count;
<------>return count;
}
 
static int qcom_rmtfs_mem_release(struct inode *inode, struct file *filp)
{
<------>struct qcom_rmtfs_mem *rmtfs_mem = filp->private_data;
 
<------>put_device(&rmtfs_mem->dev);
 
<------>return 0;
}
 
static struct class rmtfs_class = {
<------>.owner          = THIS_MODULE,
<------>.name           = "rmtfs",
};
 
static int qcom_rmtfs_mem_mmap(struct file *filep, struct vm_area_struct *vma)
{
<------>struct qcom_rmtfs_mem *rmtfs_mem = filep->private_data;
 
<------>if (vma->vm_end - vma->vm_start > rmtfs_mem->size) {
<------><------>dev_dbg(&rmtfs_mem->dev,
<------><------><------>"vm_end[%lu] - vm_start[%lu] [%lu] > mem->size[%pa]\n",
<------><------><------>vma->vm_end, vma->vm_start,
<------><------><------>(vma->vm_end - vma->vm_start), &rmtfs_mem->size);
<------><------>return -EINVAL;
<------>}
 
<------>vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
<------>return remap_pfn_range(vma,
<------><------><------>       vma->vm_start,
<------><------><------>       rmtfs_mem->addr >> PAGE_SHIFT,
<------><------><------>       vma->vm_end - vma->vm_start,
<------><------><------>       vma->vm_page_prot);
}
 
static const struct file_operations qcom_rmtfs_mem_fops = {
<------>.owner = THIS_MODULE,
<------>.open = qcom_rmtfs_mem_open,
<------>.read = qcom_rmtfs_mem_read,
<------>.write = qcom_rmtfs_mem_write,
<------>.release = qcom_rmtfs_mem_release,
<------>.llseek = default_llseek,
<------>.mmap = qcom_rmtfs_mem_mmap,
};
 
static void qcom_rmtfs_mem_release_device(struct device *dev)
{
<------>struct qcom_rmtfs_mem *rmtfs_mem = container_of(dev,
<------><------><------><------><------><------><------>struct qcom_rmtfs_mem,
<------><------><------><------><------><------><------>dev);
 
<------>kfree(rmtfs_mem);
}
 
static int qcom_rmtfs_mem_probe(struct platform_device *pdev)
{
<------>struct device_node *node = pdev->dev.of_node;
<------>struct qcom_scm_vmperm perms[2];
<------>struct reserved_mem *rmem;
<------>struct qcom_rmtfs_mem *rmtfs_mem;
<------>u32 client_id;
<------>u32 vmid;
<------>int ret;
 
<------>rmem = of_reserved_mem_lookup(node);
<------>if (!rmem) {
<------><------>dev_err(&pdev->dev, "failed to acquire memory region\n");
<------><------>return -EINVAL;
<------>}
 
<------>ret = of_property_read_u32(node, "qcom,client-id", &client_id);
<------>if (ret) {
<------><------>dev_err(&pdev->dev, "failed to parse \"qcom,client-id\"\n");
<------><------>return ret;
 
<------>}
 
<------>rmtfs_mem = kzalloc(sizeof(*rmtfs_mem), GFP_KERNEL);
<------>if (!rmtfs_mem)
<------><------>return -ENOMEM;
 
<------>rmtfs_mem->addr = rmem->base;
<------>rmtfs_mem->client_id = client_id;
<------>rmtfs_mem->size = rmem->size;
 
<------>device_initialize(&rmtfs_mem->dev);
<------>rmtfs_mem->dev.parent = &pdev->dev;
<------>rmtfs_mem->dev.groups = qcom_rmtfs_mem_groups;
<------>rmtfs_mem->dev.release = qcom_rmtfs_mem_release_device;
 
<------>rmtfs_mem->base = devm_memremap(&rmtfs_mem->dev, rmtfs_mem->addr,
<------><------><------><------><------>rmtfs_mem->size, MEMREMAP_WC);
<------>if (IS_ERR(rmtfs_mem->base)) {
<------><------>dev_err(&pdev->dev, "failed to remap rmtfs_mem region\n");
<------><------>ret = PTR_ERR(rmtfs_mem->base);
<------><------>goto put_device;
<------>}
 
<------>cdev_init(&rmtfs_mem->cdev, &qcom_rmtfs_mem_fops);
<------>rmtfs_mem->cdev.owner = THIS_MODULE;
 
<------>dev_set_name(&rmtfs_mem->dev, "qcom_rmtfs_mem%d", client_id);
<------>rmtfs_mem->dev.id = client_id;
<------>rmtfs_mem->dev.class = &rmtfs_class;
<------>rmtfs_mem->dev.devt = MKDEV(MAJOR(qcom_rmtfs_mem_major), client_id);
 
<------>ret = cdev_device_add(&rmtfs_mem->cdev, &rmtfs_mem->dev);
<------>if (ret) {
<------><------>dev_err(&pdev->dev, "failed to add cdev: %d\n", ret);
<------><------>goto put_device;
<------>}
 
<------>ret = of_property_read_u32(node, "qcom,vmid", &vmid);
<------>if (ret < 0 && ret != -EINVAL) {
<------><------>dev_err(&pdev->dev, "failed to parse qcom,vmid\n");
<------><------>goto remove_cdev;
<------>} else if (!ret) {
<------><------>if (!qcom_scm_is_available()) {
<------><------><------>ret = -EPROBE_DEFER;
<------><------><------>goto remove_cdev;
<------><------>}
 
<------><------>perms[0].vmid = QCOM_SCM_VMID_HLOS;
<------><------>perms[0].perm = QCOM_SCM_PERM_RW;
<------><------>perms[1].vmid = vmid;
<------><------>perms[1].perm = QCOM_SCM_PERM_RW;
 
<------><------>rmtfs_mem->perms = BIT(QCOM_SCM_VMID_HLOS);
<------><------>ret = qcom_scm_assign_mem(rmtfs_mem->addr, rmtfs_mem->size,
<------><------><------><------><------>  &rmtfs_mem->perms, perms, 2);
<------><------>if (ret < 0) {
<------><------><------>dev_err(&pdev->dev, "assign memory failed\n");
<------><------><------>goto remove_cdev;
<------><------>}
<------>}
 
<------>dev_set_drvdata(&pdev->dev, rmtfs_mem);
 
<------>return 0;
 
remove_cdev:
<------>cdev_device_del(&rmtfs_mem->cdev, &rmtfs_mem->dev);
put_device:
<------>put_device(&rmtfs_mem->dev);
 
<------>return ret;
}
 
static int qcom_rmtfs_mem_remove(struct platform_device *pdev)
{
<------>struct qcom_rmtfs_mem *rmtfs_mem = dev_get_drvdata(&pdev->dev);
<------>struct qcom_scm_vmperm perm;
 
<------>if (rmtfs_mem->perms) {
<------><------>perm.vmid = QCOM_SCM_VMID_HLOS;
<------><------>perm.perm = QCOM_SCM_PERM_RW;
 
<------><------>qcom_scm_assign_mem(rmtfs_mem->addr, rmtfs_mem->size,
<------><------><------><------>    &rmtfs_mem->perms, &perm, 1);
<------>}
 
<------>cdev_device_del(&rmtfs_mem->cdev, &rmtfs_mem->dev);
<------>put_device(&rmtfs_mem->dev);
 
<------>return 0;
}
 
static const struct of_device_id qcom_rmtfs_mem_of_match[] = {
<------>{ .compatible = "qcom,rmtfs-mem" },
<------>{}
};
MODULE_DEVICE_TABLE(of, qcom_rmtfs_mem_of_match);
 
static struct platform_driver qcom_rmtfs_mem_driver = {
<------>.probe = qcom_rmtfs_mem_probe,
<------>.remove = qcom_rmtfs_mem_remove,
<------>.driver  = {
<------><------>.name  = "qcom_rmtfs_mem",
<------><------>.of_match_table = qcom_rmtfs_mem_of_match,
<------>},
};
 
static int __init qcom_rmtfs_mem_init(void)
{
<------>int ret;
 
<------>ret = class_register(&rmtfs_class);
<------>if (ret)
<------><------>return ret;
 
<------>ret = alloc_chrdev_region(&qcom_rmtfs_mem_major, 0,
<------><------><------><------>  QCOM_RMTFS_MEM_DEV_MAX, "qcom_rmtfs_mem");
<------>if (ret < 0) {
<------><------>pr_err("qcom_rmtfs_mem: failed to allocate char dev region\n");
<------><------>goto unregister_class;
<------>}
 
<------>ret = platform_driver_register(&qcom_rmtfs_mem_driver);
<------>if (ret < 0) {
<------><------>pr_err("qcom_rmtfs_mem: failed to register rmtfs_mem driver\n");
<------><------>goto unregister_chrdev;
<------>}
 
<------>return 0;
 
unregister_chrdev:
<------>unregister_chrdev_region(qcom_rmtfs_mem_major, QCOM_RMTFS_MEM_DEV_MAX);
unregister_class:
<------>class_unregister(&rmtfs_class);
<------>return ret;
}
module_init(qcom_rmtfs_mem_init);
 
static void __exit qcom_rmtfs_mem_exit(void)
{
<------>platform_driver_unregister(&qcom_rmtfs_mem_driver);
<------>unregister_chrdev_region(qcom_rmtfs_mem_major, QCOM_RMTFS_MEM_DEV_MAX);
<------>class_unregister(&rmtfs_class);
}
module_exit(qcom_rmtfs_mem_exit);
 
MODULE_AUTHOR("Linaro Ltd");
MODULE_DESCRIPTION("Qualcomm Remote Filesystem memory driver");
MODULE_LICENSE("GPL v2");